1. Field of the Invention
Splicers of this general type support a pair of web rolls which alternately feed a web to a web-consuming machine which may be a printing press, for example. While web is being drawn from one roll to the machine, the leading edge of the other roll is prepared and located at the proper position in the splicer's splicer head. When the running web is about to expire, a splice ready sequence is initiated which brakes the running web to a halt, presses the prepared leading end of the ready web against the stationary running web, severs the running web just upstream of the splice and then accelerates the web up to line speed so that it now draws from the roll of ready web. A web festoon or accumulator is located between the splicer head and the downstream press or other web-consuming machine so that that machine can operate continuously during the splice sequence drawing its web requirements from the accumulator. Following the splice sequence, the accumulator is refilled with web and the empty roll core replaced with a fresh roll whose leading edge is prepared and positioned in the splicer head for the next splice sequence.
2. The Prior Art
Prior splicers of this general type are disadvantaged because they do not permit the operator to prepare the ready web for splicing in a quick and convenient fashion, while at the same time protecting the operator from dangerous splicer parts including the web cutting knife. Those prior splicing apparatus which do try to treat those problems tend to be complicated and therefore relatively expensive to make and to maintain.
Also, in many applications, it is desirable or even necessary that the splice formed by the splicer have a short "tail" to minimize downstream tension upsets and web wastage. Indeed, in some cases, a lap splice is desired in which there is no tail at all. Such splices require that the running web be severed by the cutting knife in the splicer head very close to or even at the splice between the leading end of the ready web and the running web. In many prior splicers, this cannot be accomplished while still achieving the first-mentioned important objectives of operator convenience and safety.